Control of fig blight

Fig blight is an important disease of figs in the suburbs in recent years, which is common and harmful. In the year when the disease was prevalent, 80% of the fruit was damaged and 90% of the fruit rotted, and a large number of branches and leaves withered.

[harmful symptoms] the disease mainly harms fruits, shoots and leaves, as well as buds. Fruit damage initially produced waterlogged round disease spots on the fruit surface, and then expanded rapidly, showing slightly concave and stable, irregular rot spots. When the disease spot expands to account for more than 1/2 of the total fruit, the fruit will fall off. After falling to the ground, the diseased fruit dried and shrunk into a stiff fruit.

When the leaves were killed, they produced irregular round waterlogged brown disease spots, with wheel lines, expanded rapidly, the edge was not obvious, and sparse white mold grew on the surface when the weather was wet. When the weather is dry, the disease spot dries up and the diseased leaf falls early.

When the new shoot is damaged, it produces watery brown disease spot, and when the disease spot surrounds the branch tip, the new shoot dries up and dies.

[incidence regularity] the pathogen overwintered as oospores in the host residual tissue left on the ground. In the spring and summer of the following year, Rain Water spread to the new shoots and fruits near the ground, and germinated and invaded and began to do harm. After that, sporangia and zoospores were produced on the disease spot and were repeatedly infected by the medium of wind and rain until the oospores were formed in autumn and overwintered.

In this area, new shoots and fruits can be seen in late May, and the disease is at its peak in the rainy season. In general, the branches near the ground in the field get sick first, and then spread to the whole tree. Where the orchard is low-lying, poor drainage, low trunk clumps, branches are too dense and closed, the disease is serious.

[prevention and control methods]

(1) cleaning the countryside and eliminating the source of overwintering bacteria. Do a good job in cleaning the garden in winter and spring, cut off dead branches and diseased branches, clean the ground fallen leaves and diseased tissue, concentrate on burning, and spray Baume 3-5 degree stone sulfur mixture.

(2) Pharmaceutical protection. From late May to 20 days before fruit harvest, the medicine was sprayed every 15-20 days. The medicament can be treated with 40% carbendazim wettable powder 300 times liquid, or 50% Ruidui Manganese zinc wettable powder 800 times liquid, or 58% Ruidui Manganese zinc wettable powder 800 times liquid; 1. The Bordeaux liquid also has a good control effect, which can be protected by Bordeaux solution in the early stage, and can be prevented and treated with Ruiduo fungus after the disease. In addition, it can also be prevented by 400-500 times of 50% Fumei zinc wettable powder.

(3) strengthen field management, do a good job of ditching and drainage, reduce field humidity, remove overdense branches, properly increase fruit position, and improve the ventilation and light transmission condition of tree crown.